LIST OF ILLUSTRATIONS. 



Fig. page 



1. Bacteria in wall of healthy rabbit's appendix ... frontispiece 



2. Micro-section of vermiform appendix with obliterated lumen 8 



3. Diagram showing the circumpharyngeal ring of lymphoid 



tissue 21 



4. Diagram of the lymphoid tissue near the ileo-caecal junction 23 



5. Diagram of the human alimentary canal showing the distribu- 



tion of the subepithelial lymphatic nodules 24 



6. The protuberant and tubular types of the faucial and caecal 



tonsils 29 



7. Micro-section of pigeon's caeca 34 



8. The appendix of lagomys pusillus 37 



9. The beaver's appendix 37 



10. The porcupine's appendix 38 



11. The peccary's appendix 39 



12. The tapir's appendix 39 



13. The phalanger's appendix 40 



14. The koala's appendix 41 



Jo. The wombat's appendix 42 



16. The lemur's appendix 42 



17. The slow lemur's appendix 43 



18. The orang's appendix ... 43 



19. The gibbon's appendix 44 



20. The chimpanzee's appendix ... 44 



21. The gorilla's 'appendix 45 



22. The human appendix ... 45 



23. The rabbit's caecum and appendix 52 



24. A calyx gland in the rabbit's appendix 55 



25. The wall of the rabbit's appendix at birth, at 14 days and 



at 28 days 58 



20. Bacteria in a healthy subepithelial lymph node 61 



27. Micrococci in the lymphoid tissue of a iiealthy rabbit's tonsil 62 



28. Bacilli in the lymphoid tissue of a healthy rabbit's Peyer's 



patch 63 



29. Bacilli in the lymphoid tissue of a healthy rabbit's appendix 64 



30. Bacilli in the lymphoid tissue of a healthy rabbit's appendix 65 



31. Micro-section of a Peyer's patch from a rabbit which had 



soot administered with its food for three weeks ... 71 



